Thermometer



Patented Aug. 9, 1927 UNITED STATES PATENT OFFICE. l

cuantas H. scHULTz, or CHICAGO, ILLINOIS.

THERMOMETER.

Application leg March 9, 1922. Serial No. 542,208.'v

My present invention relates to improvements in thermometers, and has special reterence to the type of thermometers employing a thermo-sensitive elementof a solid as distinguished from a fluid nature in association with an indicator hand, and a scale provided with indicia to show in terms of a temperature scale, such as the Fahrenheit or correct temperature. which is generally obtamed from a good mercurialthermometer. The objects of my linvention are to so mount the thermo-sensitive element that the i. indicating arm may be secured to .it y'vithout pivots or bearings. thereby slmpllfying the construction and doing away with the friction and other inconveniences of bearings, and, further, mounting the thermo-sensitive element and the attached indicating arm so that these elements may be readily moved with respect to the scale so that anyone, experienced or otherwise, may' readily and correctly set the instrument by reference to a dependable thermometer. It will also be hereinafter seen that the arrangement I` employ for mounting the thermo-sensitive e`ement and the indicator hand carried thereby aiords ready facility for the adjustment of the thermo-sensitive element by bending so that it will be Wholly free in its movements from contact and friction with the holden or container for the thermo-- sensitive element and will permit the positioning or centering of the stud carrying the indicator hand substantially in the center of the convolute of the thermo-sensitive element, and also substantially of the apertnre structure shown in Fig. 1, taken on line 2 2, thereof. l Y Fig. 3- is a. rear view of the structures shown in Figs. 1 and4 2.

Fig. 4 is a detail section on line 4 4, Fig v v Fig. y5 is an e'evation of the thermo-sensitive element and the housing therefor with the cap or cover removed. e

The thermometer consists of a casing comprising a cylindrical body element 6 into one end of which is inserted 'a-back7 provided with an adjusting aperture 8 and air circulatinar apertures 9,and also'fhas cut from its body adjacent its edges laterall strips 10 which are bent inwardlyand are of sufficient.

length to serve as positioning elements for af'dial plate'll. The back is also provided with tongues 12 perforated, as at 13, for suspending the instrument,l which tongues may be secured to the'back in any suitable manner, such as by rivets 14. The back is` held in suitable relation with theelement 6 by turning overthe edges of the body element, as' at 15. The body element is provided with perfor'ations 16 to facilitate the circulation of air through the instrument and around the thermo-sensitive element.

The dial plate 11 is perforated, at 17, for the passage of the pin 18 which holds the pointer or indicatingiarm 19, and with the center of thisV perforation 17 as a center suitable indicia 20 are provided upon the opposite portion of the dial in acircular path adjacent the end of the pointer or indicating arm.

-The thermo-sensitive element a .ribbon 21 'of suitable thermo-sensitive material formed into a convolute. The outer end 22 of this convolute is secured between an inwardly punched tang 23 and thesidewall of a cylindrical container 24 which is of suitable depth or thickness to accommodate the ribbons or thermo-senstitive material Without` contacting the same at any point except at the point of attachment.

The central portion of the cylindrical container 24 is provided with a circular perforation through which it is secured to the hole in dial 11 by an eyelet 25 lso applied as to produce frictionV between thecontainer and the dial, but to permit of the rotation of the container with respect to the dial. The indicating arm 1 9, as before-stated, is carried upon a pin 18 which extends through consists of.

opening 17 in the dial and has frictional engagement with the innermost coil 27 of the thermo-sensitive element. A cover 28 tits lirictionally and tightly over the cylindrical container 24, and in this cover is provided a central angular aperture 29 into which an angular instrument or key 30 is inserted to rotate the container and set the hand with respect to the scale. This key is most conveniently inserted through the key opening 8 in the back 7, but adjustment may also be secured by inserting a suitable instrument through apertures 16 in casing 6, the inner end ot' which instrument may be engaged with lateral openings 31 in the sides of the cylindrical container.

Mounted in front of the plate or dial ll. and suitably spaced therefrom and from the hand or pointer is a closure in the form of a glass disk 32, that is held in position by the usual bevel 33 to exclude dust and foreign matter from the front of the thermometer.

`While have illustrated and described a specific form of my invention it is obvious that changes may be made in the construction and arrangement of the parts Without departing from the principles thereof, and l. desire it understood that all such changes are fully contemplated Within the scope of the appended claims.

1What l claim is 1. A thermometer comprising an apermaaar@ tured disk having ascale concentric with said aperture, a centrally apertured containen, an eyelet co-operating with 'the apertures in said disk and container for securing' the same pivotally with relation to eachother, a coiled thermo' sensitive element Within said container and secured at its outer end to the peripheral Wall of said container, a pin secured to the inner end of said thermo sensitive element and extending through the aperture in said container, and a pointer secured to the outer end of said pin in coy operative relation with the scale on said disk.

2. A thermometer comprising an apertured plate, a scale therein concentric 'with said aperture, an arm movable with respect to said scale, a spindle upon Which said arm Signed at Chicagoycounty of Cook and State of Illinois, this 6th day of March, 1922.

CHARLES H. SCHULTZ. 

